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S. R. SMITH 8213. MYERS.

HEAD'BLOGK.

NO. 271 747. Patented Feb; 6, 1883.

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HEAD BLOOK.

Patented Feb. 6, 1.883.

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S. B. SMITH 81: E. MYERS.

HEAD BLOCK.

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UNITED STATES PATENT I ric v SAMUEL It. SMITH AND EDVABD MYERS, OF CINCINNATI, OHIO, ASSIGNORS TO SMITH, M YERS & SGHNIER, OF SAME PLACE.

' trncted position.

' the log-dog retracted and the hoard-dogratchet-wheels, and having'pivoted to its opn .40

HEAD-BLOCK.

SPECIFICATION forming part. of Letters Patent No. 271,747, dated February 6, 1883.

' Application tiled July :1, 1882. (No model.)

T 0 all whom it may concern Be it known that we, SAMUEL B. SMITH and EDWARD MYERS, both of Cincinnati, Hamilton county, Ohio, have invented new and useful Improvements in Saw-Mill Dogging Mechanism, of which-the following is a specification.

Our invention relates to improved dogging mechanism that enables the secure retentionot' asquard log or a plank in place upon the headblock until and during the very last out, or the secure retention of a board or'plankfor ripping.

In the accompanying drawings, Figure 1 is a side elevation, (omitting the hand-wheel,) and Fig. 2 is a top \lBW, of our knee-setting mech; anism. Fig. 3 is a side elevation of our dogging mechanism, with the board-dog in its re- Fig. 4 is a side and Fig. 5 an edge view, showing the boarddog advanced to the vertical position. Fig. 6 shows dropped to its effective position. resents our attachment in position.

A, B, and C may represent respectively portions of the track, the carriage, and t-heheadblock sills of a saw-mill. k

B may represent the customary settingscrew, occupying nut projection E from knee 1 The screw 1) carries the accustomed miter-wheel,G,which gears'with two other miters, H and H,ot' which wheel H is fast upon shaft I, and wheel 11 revolves loosely thereon. and is attached to a ratchet-wheel, J, which consequently, in like manner, revolves loosely on said shaft. Firmly keyed to said shat't I is a Fig. 7 repratchet-wheel, J, similar to-wheel J, but with its teeth pointed in the reverse direction.

K is a lever centered on shaft I between the posite sides two similar but reversely-directed pawls, L L, whose pressure upon their respective ratchet-wheels is maintained by springs M M, which bear against the heels l l of said pawls. These pawls are capableot' being released from their ratchets by a wedge, N

which occupies a guide-slot, k, in lever K, and

which is connected byhar O with wrist p on cam P, having handle 1?. Partial rotation of said cam operates to force the wedge downward and, by pressing against the pawl-heels, to lift the pawls clear of the ratchets. Such release of the pawls permits the sawyer to quicklyretract the knees by a brisk retrograde rotation of hand-wheel Q.

So attached as to vibrate concentrically with shaft I is an arm, R, in whose outer extremity A lateral projection, s, from the pawl S serves as a stop to limit the forward stroke of the lever, and also to preventthe accidental raising of pawl L. The retrograde stroke of the lever K is limited by stop V, in which a cavity or pocket, 1;, receives the pawl L and prevents I it's accidental disengagement from the ratchet. Both pawls being thns guarded against disengagement, false and irregular setting of the knees is made impossible. The distance apart. of the consecutive notches t is such as to correspond with a shift of the knees through the smallest fraction of an inch--say one thirty-second-by which different thicknesses of mill-lumber are distinguished. cut that after the pawl S has been dropped into the selected notch each forward stroke of the lever Knecessarilyshit'ts the knees a given distance, and thus uniform thickness of cut is obtained. The shaft I is,'as usual in sawmills, of sufficient length to communicate with a precisely identical headblock' mechanism at the other extremity of the carriage.

Our log and board dogging mechanismis of the following construction: Pivoted to the rear portion of any suitable knee, F, are two hubs, 1 2, from which project handles or levers 34. From hub l rigidly projects a hooked bar or rod, 5, which constitutes the log-dog. A helical spring, 6, serves to retain the log 'dog either to its active condition, as in Figs.

3, 4, and 5, or to itsiinactive or retracted condition, as in Fig. 6. The attachment of the spring 6 at one end to the knee and at the other end to the lever 3 is such that any movement of the levereither from its extreme forward or from its extreme rearward position It is appar- 7 operates to lengthen the spring, and is consequently opposed by it until the lever has been moved past the middle position of its stroke, where the spring then acts to complete the stroke and to bring and securely retain thelever to eitherits dogging or inactive condition, as the case may be. Pivoted to the knee near its front isa vibrating stanchion, 7-,whose backward play is limited by yoke 8. Fitted to and sliding upon stanchion 7 is a sheath, 9, which hasa series of notches, 9, for optional reception of the pawl 10, pivoted to holder 11 ot' the spike 12, which constitutes our board-dog Y proper.; The pawl is held. securely to any notch in which it may be placed, for the time being, by spring 13. Hub 2 is connected with sheath 9 by toggle 14 15, of which the member 14 is bolted fast to and projects rigidly from the hub, while member 15 is at one extiemity united by joint 16 to the extremity of member 14 and at its other extremity is pivoted to the sheath 9, near the upper endot'the latter. a

In the conditionoi' toggle shown in Figs. 3, 4, and 5, the board-dog proper or spike, 12, is held to the elevated position indicated in those figures. A slight elevation of lever 4 flexes thejoiut 16 and permits the sheath, with its dog, to drop to the position shown in Fig. 6, so as to engage with the top of the log near the squared side of the same or with the upper edge of a plank or board, as the case may be. Thejoint 16 is so formed as to be capablc ot' flexure only in the direction of the standard, as shown, and to be stifi' in the reverse direction, similar to the toggle-joints of buggy-hoods. Thus both dogs are securely held either in or out of action.

In operating our compound dogging mechanism the log-dog is iirstbrought into service to hold the round log, which having been squared on two adjacent sides in the usual way and placed with its squared sides respectively against the head-block sill and the knee-wall, the boarddog is then engaged in such notch 9 of sheath 9 as that when it is permitted to descend, as in Fig. 6, it will en-' gage with the log. When the log has been so far reduced as to bring the log-dog in the way of the saw, said dog may be shifted to a part of the log more distant from the sawpath or withdrawn altogether, and in either case the log will be firmly and immovably held by the board-dog until completion of the very last out.

We are aware that a saw-mill doghas been caused to engage inthe log by the action of a spring, and that the bit or dog proper has been capable of both vertical and horizontal adjustment on bars both rigid and pivoted, and that log and board dogs have been associated in the same mill. We therefore disclaim novelty in such devices, broadly considered.

We reserve the right to embody the subjectmatter of the knee-setting mechanism in a separate application for Letters Patent.

We claim as new and of our invention 1. In a saw-mill dogging mechanism, the combination of knee F, huh I, lever 3, hooked bar or rod 5, and the spring 6, whose attach- 7o ment'to the lever 3 is such as to hold it either to the retracted or protracted position when left at liberty, substantially as set forth.

2. The combination, with the board-dog 12 upon the vibrating stanchion 7, of the toggle 14 15 16, for holding said dog securely either to the retracted or protracted position, substantially as set forth.

3. In a board-dogging mechanism, the combinatiouot' hub 2, with its attached lever 4, 8c the vibrating stanchion 7, pivoted to the knee, the stop 8, the sliding sheath 9 9, the adj ustable holder 10 ll 13, the dog 12, and the toggle 14 15 16, substantially as set forth.

In testimony of which invention we hereunto 8 setour hands.

SAML. E. SMITH. EDWARD MYERS.

Atiest GEo. H. KNIGHT, SAME. S. CARPENTER. 

